CRITICAL BUG FIX: is_echo_request() and track_icmp() were reading
ctx.packet[0] thinking it was the ICMP type byte. But ctx.packet is
the IP packet, so offset 0 is the IP version/IHL byte (0x45 for IPv4).
Result: ICMP echo detection NEVER matched Type 8 packets.
- ICMP rate limiting (R32) was a no-op — wrong byte read
- ICMP echo tracking in track_icmp() was checking IP version vs 8/128
Fixed: read ICMP type from offset for IPv4, or offset 40 for IPv6.
ALSO: separate TCP SYN and ICMP echo rate limit maps.
Previously both shared one BTreeMap, so a host doing 100 TCP SYNs
+ 1 ICMP echo would be over-limit. Now each has its own budget.
NEW TESTS (4 conntrack + 5 filter table = 9 total, all passing):
- syn_limit_triggers_after_threshold
- icmp_limit_triggers_after_threshold
- syn_and_icmp_have_independent_budgets
- non_syn_tcp_does_not_count_against_syn_limit
These tests caught the ICMP type bug — failed before fix, pass after.
Red Bear OS
aa6bf0f2ea